


A heated Game

by Shadowinflame



Series: Things Inspired by Twitter [1]
Category: Undertale (Video Game)
Genre: Collars, Crosstale Sans (Undertale), Crosstale Sans/Dreamtale Sans | Dream (Undertale), Dreamtale Sans | Dream (Undertale), Ecto-Breasts (Undertale), Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Vagina (Undertale), Ectobiology, Inflation, Knotting, M/M, Mating Cycles/In Heat, Pet Play, Praise Kink, Skeleton in heat, collaring, cumflation
Language: English
Status: Completed
Published: 2020-10-02
Updated: 2020-10-02
Packaged: 2021-03-07 17:21:46
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,022
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26781334
Author URL: https://archiveofourown.org/users/Shadowinflame/pseuds/Shadowinflame
Summary: Cross is a good pet and Dream decides to reward his 'dog in heat'. It goes a little out of hand, but it's totally consensual!
Relationships: Dream/Cross, Sans/Sans (Undertale)
Series: Things Inspired by Twitter [1]
Series URL: https://archiveofourown.org/series/1963651
Comments: 4
Kudos: 104





	A heated Game

**Author's Note:**

> That is.. my first time writing knotting.. and pet play..  
> I blame Twitter.

Cross had obediently followed Dream on his weird errand today, held on a leash by the smaller one. But as Dream announced their last stop would be Underlust his knees got weak. The constantly present smell of pheromones in that AU did nothing but make his heat worse and the knowing stares he got from the inhabitants pierced straight through his soul. 

Luckily, Dream knew exactly where he needed to go and they were done within minutes. Once he had what he wanted Dream opened a portal and lead Cross through. Cross sighed as he finally stepped back into their shared home.

“Stay here for a moment, I'll just bring these things somewhere else”, Dream hummed and gave Cross a quick kiss to the forehead. 

Cross nodded and stayed exactly where Dream left him, waiting for the other to return. 

After Dream returned he shut the door behind himself and started undressing. Cross just stared at him, not sure what to say. Dream uncaringly left his clothes on the floor and lay down on the bed, the leash that still connected to Cross' collar in a firm grip. 

“You did well today”, he hummed, spreading his legs and showing his pelvis to Cross. “So I thought you deserve a reward.” Dream formed his ecto, pussy already dripping in anticipation and Cross really had to hold back as Dream dragged Cross over by the leash. “Now, be a good dog and show me your ears and tail, okay? And while you're at it, might as well form the rest of your ecto.”

Cross did as he was told and within seconds his clothes visibly filled out and a purple tail and ears formed on their respective places. 

“Strip for me”, Dream rasped. “And you better hurry, I won't wait forever.”

Cross' whole face lit up and he started fumbling with his outfit, trying to get out of as many layers at once as he could. Dream just smiled, never before had he seen Cross so eager to get out of his clothes. He was surprised as Cross really managed to undress in record speed, but looking at the mess that fell to the floor he already knew it would take both of them hours to untangle all parts of his outfit out of each other later. 

Finally undressed Cross looked at Dream in uncertain anticipation. His cock was already hard and twitching, a huge knot visible on the last third of it.

“Very well done”, Dream smirked. “Your control has gotten better lately”, he praised Cross. “Look at you still holding back even though you probably can't wait to put it in me. And now”, Dream leaned forward, taking Cross face into his hands, “fuck me like the dog in heat you are.”

That was it. Cross broke, heat taking him over completely as he slammed Dream down into the bed and climbed on top of him, rubbing his dick against Dream's pussy a few times before he rammed it into him all at once. 

Dream screamed out in pleasure, getting exactly what he wanted as Cross started pounding into him hard. 

“Aah, C-cross”, he moaned, reaching up to touch the other's ears. Cross' head snapped around, looking at Dream through hazed eyes. He leaned down and nuzzled against Dream's cheek, purring while he still fucked into Dream at a fast pace. 

“Good boy”, Dream whispered, scratching behind Cross' ear. 

Cross started shaking, his whole body trembling and Dream screamed out as he felt the knot press against his entrance with each one of the other's thrusts. With the next strong thrust it entered him and Dream clung against Cross' shoulders. 

“C-cross?”, he moaned. It was a first for the other to be that rough with him, but Dream enjoyed it. From all the timed they had sex together, Cross never even attempted to press the knot in. Now that it was inside of him, getting pressed just a little deeper with every thrust Dream found himself enjoying it a lot. 

Cross whined, pleasure running through him from being that deep inside his lover. He trust into Dream hard a last time before he came, filling Dream's beautiful yellow ecto with his own purple magic. Once he was done he attempted to pull out but the knot made it impossible to do so and due to his heat he got hard almost immediately again. 

“D-dream”, he moaned as he resumed thrusting into the smaller one's pussy. “Dream, Dream.. I love you.”

Tears rose to Dream's eyes as he felt the already huge load of cum get moved around in his stomach but he moved his hands back up to Cross' face, caressing the other's cheeks before he pulled him down into a kiss.

“I love you too”, he said as he pulled away again. “Cross..”

Cross lifted Dream up and turned him over, making him kneel on the bed while he held his upper body, hands reaching around to play with Dream's small breasts. Dream moaned as Cross' skilled hands massaged his them, fingers rubbing over his nipples, tugging just ever so slightly. Dream leaned is head back against Cross' shoulder, arms reaching behind himself to wrap around Cross' neck. He was getting close. 

Cross notices it and he licked the fingers of his right hand before guiding it down to rub against Dream's clit. He barely touched it and Dream came, moaning Cross' name out loud as his grip on the other tightened. 

Their fluids mixed in Dream's stomach, the knot not letting anything flow out. Rocking against the other's warm magic, Cross felt himself get close again and pulled Dream into another kiss. His hand moved up from Dream's clit to touch his stomach so he could feel it starting to bulge as he came a second time.

Both of them were left panting, gasping for breath they didn't need as the knot finally let up and Cross pulled out of Dream. Both of them laid down on the bed for a moment.  
“What a good pet”, Dream breathed as he leaned into Cross, who was still caressing the other's stomach.

**Author's Note:**

> Idk, man.


End file.
